Air Mauritius - I know they have constantly updated their A340 with newer built leased aircraft. Does anyone know if they will upgrade to the A340-500?

Air Tahiti Nui - From what I understand, Air Tahiti Nui took delivery of a new build A340 from Airbus very recently. Was that a -300 model and will that replace or augment their existing aircraft (one A340-200).

Also, is the A340-500 a good replacement for the A340-300X or is it a totally upgraded model that is only efficient on very long flights.

Air Tahiti Nui ordered two A430-300, to replace its sole A340-200 and to expand.
As for the A340-500, I have only heard about it in relation to ultra-longhaul flights ... plus its slighly bigger than the A340-300. I doubt the A345 would bring any "useful" destinations into nonstop range from Mauritius / Papeete that the A340-300 can't fly to. The A345 can't fly Papeete-Paris nonstop.